Metal staircase



March' l2, 194@o R. c. sKEEl. Er AL 2,193,146

METAL STAIRCASE Filed Jan. l5, 1939 NNI 75 Il Patented Mar. 12, 1940 PATENT oEFicE METAL STAIRCASE Ray C. Skeel, Poland, and Wolfgang W. Krauss, Youngstown, Ohio, assignors to Truscon Steel Company, Youngstown, Ohio, a corporation of Michigan` Application January 13, 1939, Serial No.` 250,859

4 Claims.

This invention relates to metal staircases of the `type used in homes or industrial buildings, on shipboard or other places `where a strong and durable reproof stairway isy required- Primarily the present invention provides a rigid"and stable metal staircase wherein the tread members of the steps carry angle members whose vertical legs are suitably spaced from the stringers and secured thereto by a plug weld,

which shrinks upon cooling and draws thesaid vertical flange or leg toward the Stringer to thus `unite the steps including the treads with the` stringers under tension.

A further object of the invention is to provide tread members having front and rear edge portions which mate or nest with complemental parts with the riser sections and which also coperate to provide a recess or cavity for receiving a suitable tread material which may be renewed from time to time if desired. In that connection,V the invention contemplates the use of tread members andriser sections which may be readily made by pressing, rollingv or braking operations and readily assembled with facility togprovide a stairway in which all of the parts are held together by welding.

With the above and other objects in view which will more readily appear as the nature of the` invention is better understood, the same consists inthe novel construction, combination and arrangement of parts hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown n the accompanying drawing in which:

Figure 1 is a partial vertical sectional view of a staircase embodying the present improvements.

Figure 2 is a vertical sectional View taken on the line 2 2 of Fig 1.

Figure 3 is a detail elevation of a portion of the lower step and the bottom endof the Stringer.

Similar reference characters designate corresponding parts throughout the several figures of the drawing.

Referring to the drawing, it may be observed that the staircase includes opposite Stringer members which are similar but opposite hand, rand therefore only one of them is shown. These Stringer members designated generally as I are preferably of channel formation as will be apparent from Figure 2, and the lower end thereof may be closed by `a suitable flange 2 welded as' at 3 to the upper flange of the Stringer. The upper end of the Stringer is provided with an anchor or tie member 4 which is` preferably of angular `formation having one leg of the angle cut away as indicated at 5 and welded to the inside face of the Stringer.l The angular body li of the tie member may be provided with Suitable Openings to assist in anchoring the Stringer to the upper oor of the building.

Each of the steps carried bythe stringers comprises a tread member and a riser section. Referring first to the treadmember it will beobserved that the Same includes a body portion 5 having an outwardly and downwardly curved front edge l and anup-wardly directed heel flange Each of the risers comprises a plate portion 9 provided at its upper edge with an outwardly and inwardly directed toe flange I0 which is curved on an arc of longer radius but having the same axis as the arc describing the flange `'l of the tread so that these parts may be nested togetherand the toe flange I@ of the riser masks thefront flange of the tread. The lower'edge of the riser 9 is formed with an outiw'ardly" directed fiange Il. `When the treads 6 and risers 9 are assembled to form a step, it Will be observed from Figure Lithat the thickness of the metal of the risers, at the terminal edges of the flanges IB and `I I, provides a recess or cavity I2 for receiving suitable tread material I3 which may be a mastic composition, linoleum, rubber or any other desired tread material. The tread members 6 and the riser sections 9 are united by suitable welds `Ill located at spaced intervals along the edges of the overlapped portions 3 and 9, respectively, of the treads and risers, and also along the inner edges of the nested flange portions 'l and Ill respectively of the treads andl risers. yIn practice, the treads and risers forming the individual steps have their end portions in abutting relation with the vertical side Walls of the stringers l and the completed steps are firmly and rigidly united with the stringers in the manner now to be described. i

of the Stringer. It will be observed from Figures i 1 and 2 the legs I6 of the angle members are provided with suitable openings to receive the welding'material l'l. When the united treads and riser members forming the steps are clamped between the metallic stringers. the weld metal Il is deposited by electric arc, Oxy-acetylene or other welding method within the openings provided in iange i6. This molten weld metal fuses with the surface of Stringer i and edge of opening in flange it, thus forming a plug weld, usually filling the hole. As the weld cools and shrinks the flange 6 of the member A will be drawn toward the Stringer members and, thus, the edges of the treads and risers and the inner faces of the stringer members which abut 'will be rmly and rigidly united under tension. and thus stabilize the entire structure, and, at the same time, form a rm and tight union between the steps and the stringers. Although a plug weld has been shown and described, the same result may be obtained by a rivet weld. In the latter caseA the stringer as well as the ange i6 are provided with pre-punched registering openings and when the welding is done, one side is backed up by a copper block and the nished job results in a rivet of deposited metal whichY passes through both members instead of one.

From the foregoing it will be apparent that the present invention provides a simple and practical staircase construction wherein the treads and risers are directly in surface contact at both the toefand heel of the tread, thereby 'obtaining th benet of the reinforcing'eiect of closely nesting parts while at the same time providing a recess or trough for the tread material. Moreover, when the treads and risers are united in step formation, they are rigidly united and connected under tension with the stringers insuch a way as to form a drum tight connection therebetween.

We claim:

i. A staircase, including, in combination, metallic stringers, step units formed by interfitting metallic tread and riser sections having their side edges abutting the stringers, a, member carried by the tread and spaced from the face of the Stringer, and means connecting said member and Stringer comprising a weld which shrinks upon cooling, thereby to draw the edges of the step units against the stringers under tension.

2. A staircase, including, in combination, metallic strihgers,V step units formed by interfitting metallic tread and riser sections, and means for securing said steps rigidly to the stringers, said V'means including angle members having their horizontal legs welded to the undersides of the treads at a point inwardly of the side edge of the tread .so as to space the vertical legs of the angles away from the sides of the stringers, and plug welds connecting the said vertical legs to the stringers'under tension due to shrinking of the .weld upon cooling.

3. A staircase, including, in combination, metallic stringere, stepy units each including a tread having its side edges abutting the stringers, a member carried by each end of each tread and spaced from the face of the adjacent Stringer, and means connecting each member and adjacent stringer and comprising a weld which shrinks upon cooling, thereby to draw the edges of the step units against the stringers under tension. 4

4. A staircase, including, in combination, metallic stringers, step units each including a tread having its side edges abutting the stringers, and means for securing said treads rigidly to the stringers, said means including angle members having horizontal legs welded to the undersides of the treads at points inwardly of the side edges of the treads so as to space the vertical legs of the angles away from the sides of the stringers, and plug welds connecting the said vertical legs to the stringers under tension due to shrinking of the welds upon cooling.

RAY C. SKEEL. WOLFGANG W. KRAUSS. 

